'Extrude cut' in an assembly. Disjoint body error occurs?

Hello all,

I am making an extruded cut in an assembly.

The rectangular cut boundary sketch surrounds the parts that need to be chopped. - See picture below

However, the cut does not cut through one of the components as the picture below shows.

Also i have found this is spr  189296.

Would anyone know a way around this?

Many thanks.

SolidworksAssemblies